Coastal structures II

Submerged coastal structures modify incident wave fields and alter nearshore processes. Existing research indicates that our understanding of hydrodynamics and sediment transport resulting from wave-reef interactions is still incomplete. Here we present the findings of an extensive set of wave basin experiments reproducing the wave-driven hydrodynamics around reefs subject to a range of wave conditions and water levels. Through a generalized reef design and variations in key reef geometrical properties, we aimed to enhance the understanding of nearshore hydrodynamics applicable to various submerged coastal structures, including nature-based artificial reefs. Overall, this study improves the understanding of far-field scale hydrodynamic processes resulting from waves interacting with artificial reefs. The novel laboratory dataset developed by this research provides a foundation for developing improved predictive models and guidelines to design artificial reefs for coastal protection.

A physical experiment was performed to seek an empirical equation predicting the wave force acting on the upper surface of the pavement behind the revetment parapet due to wave overtopping as well as the uplift force acting on the underlayer of the pavement induced by the wave pressure passing through the core layers of the revetment. The experiment was carried out by installing pressure transducers along the upside and downside of the pavement with different configuration of the parapet, water depth, relative freeboard, and armor layer thickness. Then, the wave pressure and force on the pavement was analyzed under various incoming wave conditions. Based on the analysis results, major parameters affecting the wave forces were identified and an empirical equation for evaluating the forces on the pavement is suggested.

The potential of predictive maintenance for critical port infrastructure, reducing risks and extending its life cycle, remains to be unlocked by suitable quantitative information that fosters predictive maintenance and sustained investments towards progressive climate-proofing of the infrastructure. The PI-BREAK (Predictive Intelligent system for BREAKwater maintenance) project apply state-of-the-art monitoring and modelling techniques to the maintenance of the Punta Lucero rubble mound breakwater in the port of Bilbao, Spain. Among the tasks performed in the project, 3D physical model tests have been performed at the directional wave tank named "TOD" from IHCantabria, to assess the breakwater performance and analyze risk levels with and without maintenance interventions. From the different configurations tested at the TOD basin, some will serve as a wave breaking benchmark to be shared with the scientific community.

Coastal flooding from high surges and extreme waves induced by hurricanes and tsunamis significantly threatens low-elevated regions. Moreover, the sea level rise, derived from climate change, has resulted in shorelines advancing towards the land, exacerbating the flooding-induced damage in coastal communities. It is necessary to implement coastal structures to mitigate the influence of extreme flooding on coastal regions. Seawalls, submerged breakwaters, and mangrove forests have been constructed worldwide to attenuate wave overflows and damage in near-coast areas. However, studies on the comprehensive intercomparison of the protective performance of each measure against flooding to provide guidelines in coastal design and planning have yet to be limited. Therefore, the current study conducted experimental and numerical models to investigate the efficiency of natural (mangroves) and man-made (seawall and submerged breakwater) structures in mitigating forces, pressures, and hydrodynamics generated by overflows in a series of building arrays characterizing coastal communities.